I. Field of the Invention
The present invention relates generally to systems for supporting skis, ski mobiles and the like on mobile platforms. More particularly, the present invention relates to an adjustable, quick-acting locking mechanism for securely maintaining skis, particularly the skis of a snowmobile or other ski-based vehicle, against a surface, such as the upper surface of a trailer bed. The present invention is a mechanism for securely clamping skis to the upper surface that is easy to use, simple to install and disassemble, and provides a swift actuator for quick locking and unlocking of the skis from the upper surface.
II. Description of the Prior Art
Skis, such as snow skis or water skis, are generally used on snow or water surfaces and are transported over dry land by a supporting mechanism, such as a ski rack. Conventional ski racks attach to the roof, trunk or bumper of an automobile and support the skis during transit. Examples of such ski racks are provided in U.S. Pat. No. 4,143,799 to R. W. Dietlein, et al., which issued on Mar. 13, 1979, titled SKI RACK FOR VEHICLES; U.S. Pat. No. 4,312,467 to R. Kulwin, which issued on Jan. 26, 1982, titled DOUBLE TIER AUTOMOTIVE SKI RACK; and U.S. Pat. No. 4,717,055 to A. San Juan, which issued on Jan. 5, 1988, titled BRACKET FOR TRUNK MOUNTING SKI OR SURFBOARD RACK. However, these conventional ski racks are complicated mechanisms that require much time and effort to secure and remove the skis. Likewise, attachment and detachment of the ski rack to and from the automobile are also time consuming and difficult.
Similarly, ski-based vehicles, such as snowmobiles and jet skis, are also transported over dry land. These ski-based vehicles are transported by a mobile platforms, such as a trailer bed, that includes a locking mechanism to anchor the vehicle to the platform during transit and/or to prevent theft of the vehicle. For example, U.S. Pat. No. 3,730,552 to R. C. Clark, which issued on May 1, 1973, titled LOAD ANCHORING DEVICE provides an anchoring device for supporting a snowmobile on the upper deck of a trailer. The anchoring device is an elongated plate having one end hinged to the upper deck and the other end attached to the back of the snowmobile.
Also, U.S. Pat. No. 3,923,335 to J. A. Erickson, which issued on Dec. 2, 1975, titled CAMPER UNIT FOR SNOWMOBILE TRAILERS and U.S. Pat. No. 5,387,070 to J. E. Roeling, which issued on Feb. 7, 1995, titled COUPLING SYSTEM FOR MOTORIZED VEHICLES each provide a mobile platform having an upper deck for supporting snowmobiles. The skis of the snowmobiles include a large loop at their front ends, and each mobile platform includes a rod that passes through the loop of the skis to retain the front end of the skis on the platform.
The mechanisms described in the above cited patents do not safely retain the skis of the snowmobile to the platform. Snowmobiles are large, heavy vehicles that require substantial support and security when moved. The mechanisms of the above patents rely on the weight of the snowmobiles to retain them on the platform. However, the snowmobiles' skis are not securely held against the platform and, therefore, snowmobiles are subject to violent movement during transport. Accordingly, such insecure movement of the snowmobile is dangerous and can cause damage to the snowmobile and/or the mobile platform.
Mechanisms for securely holding skis to the upper surface of a mobile platform are known. For example, U.S. Pat. No. 5,044,845 to V. J. Baker, Jr., which issued on Sep. 3, 1991, titled SNOWMOBILE TRANSPORT APPARATUS provides a locking mechanism for maintaining the skis of a snowmobile against the upper deck of a trailer. Specifically, a pair of forward slots and a corresponding pair of rear slots are formed through the mobile platform. Hook members are projected through the rear slots, and actuator handles are directed through the forward slots. To secure the snowmobile's skis to the mobile platform, a latch rod is positioned over and held against the skis by the hook members when activated by the actuator handles. However, this locking mechanism is complicated and require much time and effort to secure and remove the skis. In addition, attachment and detachment of the locking mechanism to and from the mobile platform are also time consuming and difficult.
In view of the above patents, it is apparent that mechanisms for providing a secure hold of skis against the upper surface of a mobile platform tend to be complicated and difficult to use. Analogously, the complicated design of such mechanisms are expensive to install and manufacture.
One mechanism that provides a secure hold is a mechanism that includes a lock bar placed over the skis and a clamping device situated through a middle aperture of the lock bar that clamps the lock bar downward against the skis. For example, U.S. Pat. No. 5,203,655 to D. Persau, which issued on Apr. 20, 1993, titled LOCKING BAR FOR SNOWMOBILE ON TRAILER provides a lock bar and a clamping device having a threaded shaft that passes through an aperture of the lock bar and screws into a receiving hole formed at the upper surface of a mobile platform. By rotating the entire clamping device, including its threaded shaft, the lock bar is clamped downward against the skis of a snowmobile.
However, the clamping device of U.S. Pat. No. 5,203,655 is cumbersome and awkward to use. In particular, the threaded shaft of the clamping device must be alignment with the receiving hole of the platform. This is difficult to accomplish since the lock bar obstructs the users view of the receiving hole. Also, the clamping device is unwieldy to use since the threaded shaft rotates with its respective handle and the only stationary structure for supporting the device is the receiving hole of the platform. In addition, the thread of the shaft has a progressive slope so that the lower portion of the clamping device will be securely maintained against the platform. However, due to this progressive slope, the shaft requires numerous turns in order to adjust vertically relative to the platform. Furthermore, the clamping device is difficult to remove from the platform since it must be completely unscrewed from the receiving hole. This removal process is particularly time consuming since, as stated above, the thread of the shaft has a progressive slope.
The present invention is particularly well suited for locking or otherwise supporting individual skis or a ski-based vehicle to the upper surface of a mobile platform, such as a trailer bed. In particular, the present invention is a system for locking one or more skis against an upper surface of a platform that includes a stationary shaft having a lower end that is secured to the platform and an adjustment assembly that easily mounts at the upper end for rotation about the stationary shaft. Accordingly, the stationary shaft provides solid support for the adjustment assembly and, thus, the adjustment assembly easily rotates about the shaft. In addition, the upper portion of the shaft has multistart or multilead threads that provide a quick-acting mechanism for locking and unlocking the skis to the platform, while the lower portion is securely maintained against the platform. Furthermore, a unique connection is provided between the upper and lower portions so that the adjustment assembly may be quickly and easily attached to and separated from the platform.